src/net/http/doc.go

// Copyright 2011 The Go Authors. All rights reserved.
// Use of this source code is governed by a BSD-style
// license that can be found in the LICENSE file.

/*
Package http provides HTTP client and server implementations.

[Get], [Head], [Post], and [PostForm] make HTTP (or HTTPS) requests:

	resp, err := http.Get("http://example.com/")
	...
	resp, err := http.Post("http://example.com/upload", "image/jpeg", &buf)
	...
	resp, err := http.PostForm("http://example.com/form",
		url.Values{"key": {"Value"}, "id": {"123"}})

The caller must close the response body when finished with it:

	resp, err := http.Get("http://example.com/")
	if err != nil {
		// handle error
	}
	defer resp.Body.Close()
	body, err := io.ReadAll(resp.Body)
	// ...

# Clients and Transports

For control over HTTP client headers, redirect policy, and other
settings, create a [Client]:

	client := &http.Client{
		CheckRedirect: redirectPolicyFunc,
	}

	resp, err := client.Get("http://example.com")
	// ...

	req, err := http.NewRequest("GET", "http://example.com", nil)
	// ...
	req.Header.Add("If-None-Match", `W/"wyzzy"`)
	resp, err := client.Do(req)
	// ...

For control over proxies, TLS configuration, keep-alives,
compression, and other settings, create a [Transport]:

	tr := &http.Transport{
		MaxIdleConns:       10,
		IdleConnTimeout:    30 * time.Second,
		DisableCompression: true,
	}
	client := &http.Client{Transport: tr}
	resp, err := client.Get("https://example.com")

Clients and Transports are safe for concurrent use by multiple
goroutines and for efficiency should only be created once and re-used.

# Servers

ListenAndServe starts an HTTP server with a given address and handler.
The handler is usually nil, which means to use [DefaultServeMux].
[Handle] and [HandleFunc] add handlers to [DefaultServeMux]:

	http.Handle("/foo", fooHandler)

	http.HandleFunc("/bar", func(w http.ResponseWriter, r *http.Request) {
		fmt.Fprintf(w, "Hello, %q", html.EscapeString(r.URL.Path))
	})

	log.Fatal(http.ListenAndServe(":8080", nil))

More control over the server's behavior is available by creating a
custom Server:

	s := &http.Server{
		Addr:           ":8080",
		Handler:        myHandler,
		ReadTimeout:    10 * time.Second,
		WriteTimeout:   10 * time.Second,
		MaxHeaderBytes: 1 << 20,
	}
	log.Fatal(s.ListenAndServe())

# HTTP/2

Starting with Go 1.6, the http package has transparent support for the
HTTP/2 protocol when using HTTPS. Programs that must disable HTTP/2
can do so by setting [Transport.TLSNextProto] (for clients) or
[Server.TLSNextProto] (for servers) to a non-nil, empty
map. Alternatively, the following GODEBUG settings are
currently supported:

	GODEBUG=http2client=0  # disable HTTP/2 client support
	GODEBUG=http2server=0  # disable HTTP/2 server support
	GODEBUG=http2debug=1   # enable verbose HTTP/2 debug logs
	GODEBUG=http2debug=2   # ... even more verbose, with frame dumps

Please report any issues before disabling HTTP/2 support: https://golang.org/s/http2bug

The http package's [Transport] and [Server] both automatically enable
HTTP/2 support for simple configurations. To enable HTTP/2 for more
complex configurations, to use lower-level HTTP/2 features, or to use
a newer version of Go's http2 package, import "golang.org/x/net/http2"
directly and use its ConfigureTransport and/or ConfigureServer
functions. Manually configuring HTTP/2 via the golang.org/x/net/http2
package takes precedence over the net/http package's built-in HTTP/2
support.
*/
package http